Impulsing circuit



Patented May 2, 1933 UNITED STATES PATENT OFFICE LAURENCE J. LESH, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO I ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHICAGO, ILLINOIS, A CORPORA- TION OF DELAWARE IMPUIJSING CIRCUIT Application filed August 18, 1980, Serial No. 476,226. Renewed June 27, 1982.

The present invention relates general to impulsing circuits and the main ob ect of the invention is the provision of an improved impulse repeating arrangement employing a neon tube.

The invention has a large number of contemplated uses and may be employed wherever it is necessary to repeat impulses for the purpose of operating automatic telephone equipment or the like.

A complete understanding of the invention may be had from the following specification when read in connection with the accompanying drawing, comprising one figure only, which illustrates, by means of the usual schematic diagram, one application of the invention,

The drawing illustrates the improved 1mpulse repeating arrangement used in connection with service observing equipment for automatic telephone systems such as disclosed in Patent No. 1,640,675, issued August 30, 1927, to M. Schwartz. Conductors 26, 27, and 28 represent a primary trunk accessible to primary lineswitches over bank contacts such as l, 2, and 3 and terminating in a first selector switch S. The selector switch is of the Strowger vertical and rotary type, well known in the art, and has therefore been shown in skeleton form.

Conductors 10, 11, and 12 extend to the service observing equipment which may be similar to that disclosed in the above-mentioned patent and is indicated by the rectangle at the right of the drawing. The equipment in the lower left-hand portion of the drawing represents the improved impulse-repeating arrangement according to the present invention and serves to repeat the digit impulses dialled by a calling subscriber to the recorder R which forms a part of the service observing equipment.

Referring to the impulse repeater shown in the lower left-hand portion of the drawing, the neon tube 15 and relay 16 are permanently bridged across conductors 13 and 14 which are coupled to line conductors 27 and 28 of the primary trunk bymeans of condensers 8 and 9, respectively. A battery 21 and resistance 20 in series are also bridged across conductors 13 and 14 in parallel with the neon tube 15 and relay 16. Thus there is a permanently closed circuit from positive pole of battery 21, neon tube 15, winding of relay 16, resistance 20, to the negative pole of battery 21. The voltage of the battery 21 is just below the striking point of the neon tube 15 so that normally no current flows in this circuit.

The operation of the improved impulse repeater will nowbe explained in detail. It will be assumed that a subscriber has initiated a call and that his lineswitch has seized thetrunk comprising conductors 26, 27, and 28 over bank contacts 1, 2, and 3. As soon as the trunk is seized, line relay 4 of the first selector operates over the calling loop, and at contact 6 closes the circuit of release relay 5. Relay 5 operates and at contact 7 grounds the release trunk conductor 26, thereby marking the trunk busy in the banks of the primary lineswitches, and also preparing the service observing equipment over conductor 10.

The calling subscriber now proceeds to dial the digits of the desired telephone number. When the circuit of line relay 4 is opened at the first impulse, the induced potential, due to the sudden interruption of current flow in the windings of line relay 4, is impressed on the bridge comprising neon tube 15 and relay 16 over conductors 27 and 28, condensers 8 and 9, and conductors 13 and 14. The relatively high potential across the neon tube causes the gas in the tube to ionize, decreasing the resistance of the tube and allowing current to flow in the local circuit including battery 21, neon tube 15, relay 16, and resistance 20. Relay 16 is energized, and at contact 17 closes a shunting circuit for the neon tube through relay 18.

Relay 18 energizes due to the short-circuiting current through its winding and at contact 19 repeats the impulse to the recorder R of the service observing equipment by connecting ground to conductor 22, thereby energizing the recorder magnet 106 in an obvious circuit. The impulse is recorded on the tape 23 by means of the pencil 25.

The RI drop across resistance 20, dueito 100 the shunting current through relay 18, re-

' duces the potential across the neon tube to a change in the regular manner to complete.

the connection to the called line. In addition, each impulse is repeated to the service observing equipment by means of the neon tube repeating device in the manner just described and the service observation operator is thereby informed of the number dialled by the calling subscriber.

Although the invention has been illustrated and described as applied to a service observing system for automatic telephone systems, it is to be understood that the invention is not in any Way limited to this application, but has a large number of other uses which will be at once apparent to those skilled in the art.

Having described the invention, what-is thought to be new and is desired to have protected by Letters Patent, will be ppinted out in the appended claims.

IVhat is claimed is:

1. In an impulse repeater, an incoming line and an outgoing impulsing circuit, a neon tube and a. relay bridged in series across said incoming line, a permanently closed circuit for said tube including a source of potential below the striking voltage of said tube, means for transmitting an impulse over said incoming line to cause said tube to strike thereby allowing current to flow in said circuit to operate said relay, and means controlled by said relay for shunting said tube and for repeating said impulse over said outgoing circuit.

2. An impulse repeater comprising a neon tube connected in series with a relay and a battery, the voltage of said battery being below the striking voltage of said tube, means for applying an additional voltage across said tube to cause it to strike and allow current to flow to operate said relay, and means controlled by said relay for shunting said tube to stop the fiow of'curre'nt and allow said relay to release.

3. An impulse repeater comprising a neon tube connected in series with a relay and a battery, the voltage of said battery being below the striking voltage of said tube, an outgoing impulsing circuit, means for transmitting an impulse to said repeater by applying additional voltage across said tube to cause it to strike and allow current to flow to operate said relay, and means controlled by said relay for stopping the flow of current through said tube and for repeating said impulse over said outgoing circuit.

4;. An impulse repeater comprising a neon tube connected in series with a relay and a source of potential below the striking potential of said tube, an outgoing circuit, means for transmitting an impulse to said repeater by applying additional voltage across said tube to cause it to strike and allow current to flow to operate said relay, a second relay, contacts on said first relay for bridging saidsecond relay around said tube, and contacts on said second relay for repeating said impulse over said outgoing circuit. v

5. An impulse repeater comprising a neon tube, a relay, a resistance and a battery connected in series, a second relay, contacts on said first relay for bridging said second relay in. shunt of said neon tube and said first relay and an outgoing impulsing circuit including contacts'on said second relay.

6. In a telephone system, a trunk line terminating in the line relay of an automatic switch, a branch line extending from said trunk line and terminating in a repeater comprising a neon tube and a relay bridged across said branch line, interruptions of said trunk line during the control of said switch causing said tube to flash over due to the inductive kick from said line relay when the current therein is suddenly interrupted and ermit current to flow and operate said reay, and means controlled by said relay for transmitting impulses corresponding to the interruptions of said trunk line.

7. In a telephone system, a trunk line terminating in the line relay of an automatic switch, impulses for operating said switch consisting of interruptions of said trunk line, a branch line extending from said trunk line, and a pickup device connected in said branch line and responsive to the interruptions of said trunk line, said pickup device comprising a neon tube which is caused to flash over at each interruption of said trunk line due to the inductive surge from said line relay and a relay connected in circuit with said tube and operated each time said tube flashes over.

8. In combination, a normally closed line terminating in a receiving device comprising a neon tube and a relay connected in series with a source of current, the voltage of said source being below the striking voltage of said tube, a condenser in each line conductor for preventing current flow from said source to said line, and an impedance bridged across said line in series with a battery, interruptions in the line circuit causing said neon tube to strike due to the inductive kick from said impedance when the current therein is interrupted, thereby allowing said relay to operate each time the line is opened.-

9. In a telephone system, a trunk over which impulses are transmitted to establish a telephone connection service observing equipment, a neon tube and a relay bridged in series across said trunk, a local circuit including said neon tube, said relay, and a battery whose voltage is just below the striking voltage of said tube, said tube flashing over and allowing current from said battery to flow and operate said relay each time an impulse is transmitted over said trunk, and means controlled by said relay for repeating said impulses to said service observing equipment.

10. In a telephone system, a line over which impulses are transmitted during the establishment of a telephone connection, service observing equipment, and a repeater bridged across said line for repeating said impulses to said service observing equipment, said repeater comprising a neon tube which is rendered conductive by each impulse, and means controlled by said tube for transmitting corresponding impulses to said service observing equipment.

11. In an impulse repeater, an incoming line terminating in a battery, a neon tube and a relay bridged in series across said line, the voltage of said battery being below the striking voltage of said tube, means for transmitting impulses over said line to cause said tube to strike thereby permitting current to flow to operate said relay, a resistance connected in series with said battery, the voltage drop across said resistance reducing the voltage across said tube to a value below that required to maintain the current flow therethrough thereby stopping the flow of current and allowing said relay to release, and means controlled by said relay for repeating said impulses.

12. In an impulse repeater, an incoming line terminating in a battery, a neon tube and a relay bridged in series across said line, the voltage of said battery being below the striking voltage of said tube, means for transmitting impulses over said line to cause said tube to strike, thereby permittingcurrent to flow to operate said rela an outgoing impulsing circuit, a secon relay controlled by said first relay, and contacts on said second relay included in said outgoing im ulsin circuit to re eat said im ulses thereover.

In witness whereof, I hereunto subscribe my name this 14th day of August, A. D.

LAURENCE J. LESH. 

